from PyQt5 import QtWidgets
import sys

class Window(QtWidgets.QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Test")
        self.setGeometry(100, 100, 500, 500)

app = QtWidgets.QApplication(sys.argv)

window = Window()
window.show()

sys.exit(app.exec_())